Here's why:

* Coulomb's Law: The force between two charged objects is described by Coulomb's Law:

F = k * (q1 * q2) / r²

Where:

* F is the force

* k is Coulomb's constant

* q1 and q2 are the charges of the objects

* r is the distance between the objects

* Doubling the Distance: If you double the distance (r), the denominator in the equation becomes (2r)².

* Effect on Force: (2r)² = 4r². Since the denominator is squared, doubling the distance results in the force being divided by 4 (reduced by a factor of 4).